From patchwork Thu Jul 21 10:15:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomer Maimon X-Patchwork-Id: 12924954 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0D1ACCA479 for ; Thu, 21 Jul 2022 10:15:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233142AbiGUKPp (ORCPT ); Thu, 21 Jul 2022 06:15:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233136AbiGUKPo (ORCPT ); Thu, 21 Jul 2022 06:15:44 -0400 Received: from maillog.nuvoton.com (maillog.nuvoton.com [202.39.227.15]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id AE6B42A40A; Thu, 21 Jul 2022 03:15:41 -0700 (PDT) Received: from NTHCCAS01.nuvoton.com (NTHCCAS01.nuvoton.com [10.1.8.28]) by maillog.nuvoton.com (Postfix) with ESMTP id 978021C803BA; Thu, 21 Jul 2022 18:15:40 +0800 (CST) Received: from NTHCCAS04.nuvoton.com (10.1.8.29) by NTHCCAS01.nuvoton.com (10.1.8.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2375.7; Thu, 21 Jul 2022 18:15:40 +0800 Received: from taln60.nuvoton.co.il (10.191.1.180) by NTHCCAS04.nuvoton.com (10.1.12.25) with Microsoft SMTP Server id 15.1.2176.2 via Frontend Transport; Thu, 21 Jul 2022 18:15:39 +0800 Received: by taln60.nuvoton.co.il (Postfix, from userid 10070) id 46A0363A4C; Thu, 21 Jul 2022 13:15:39 +0300 (IDT) From: Tomer Maimon To: , , , , , , , , CC: , , , , Tomer Maimon Subject: [PATCH v1 1/2] spi: npcm-pspi: add full duplex support Date: Thu, 21 Jul 2022 13:15:27 +0300 Message-ID: <20220721101528.118499-2-tmaimon77@gmail.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20220721101528.118499-1-tmaimon77@gmail.com> References: <20220721101528.118499-1-tmaimon77@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org The NPCM PSPI handler, on TX-buffer not null, would perform a dummy read but did not save the rx-data, this was valid only for half duplex. This patch adds full duplex support for NPCM PSPI driver by storing all rx-data when the Rx-buffer is defined also for TX-buffer handling. Signed-off-by: Tomer Maimon --- drivers/spi/spi-npcm-pspi.c | 75 +++++++++++++++---------------------- 1 file changed, 30 insertions(+), 45 deletions(-) diff --git a/drivers/spi/spi-npcm-pspi.c b/drivers/spi/spi-npcm-pspi.c index 1668a347e003..02f0fcceaf19 100644 --- a/drivers/spi/spi-npcm-pspi.c +++ b/drivers/spi/spi-npcm-pspi.c @@ -195,22 +195,22 @@ static void npcm_pspi_setup_transfer(struct spi_device *spi, static void npcm_pspi_send(struct npcm_pspi *priv) { int wsize; - u16 val; + u16 val = 0; wsize = min(bytes_per_word(priv->bits_per_word), priv->tx_bytes); priv->tx_bytes -= wsize; - if (!priv->tx_buf) - return; - switch (wsize) { case 1: - val = *priv->tx_buf++; + if (priv->tx_buf) + val = *priv->tx_buf++; iowrite8(val, NPCM_PSPI_DATA + priv->base); break; case 2: - val = *priv->tx_buf++; - val = *priv->tx_buf++ | (val << 8); + if (priv->tx_buf) { + val = *priv->tx_buf++; + val = *priv->tx_buf++ | (val << 8); + } iowrite16(val, NPCM_PSPI_DATA + priv->base); break; default: @@ -222,22 +222,24 @@ static void npcm_pspi_send(struct npcm_pspi *priv) static void npcm_pspi_recv(struct npcm_pspi *priv) { int rsize; - u16 val; + u16 val_16; + u8 val_8; rsize = min(bytes_per_word(priv->bits_per_word), priv->rx_bytes); priv->rx_bytes -= rsize; - if (!priv->rx_buf) - return; - switch (rsize) { case 1: - *priv->rx_buf++ = ioread8(priv->base + NPCM_PSPI_DATA); + val_8 = ioread8(priv->base + NPCM_PSPI_DATA); + if (priv->rx_buf) + *priv->rx_buf++ = val_8; break; case 2: - val = ioread16(priv->base + NPCM_PSPI_DATA); - *priv->rx_buf++ = (val >> 8); - *priv->rx_buf++ = val & 0xff; + val_16 = ioread16(priv->base + NPCM_PSPI_DATA); + if (priv->rx_buf) { + *priv->rx_buf++ = (val_16 >> 8); + *priv->rx_buf++ = val_16 & 0xff; + } break; default: WARN_ON_ONCE(1); @@ -296,43 +298,26 @@ static irqreturn_t npcm_pspi_handler(int irq, void *dev_id) struct npcm_pspi *priv = dev_id; u8 stat; - stat = ioread8(priv->base + NPCM_PSPI_STAT); - if (!priv->tx_buf && !priv->rx_buf) return IRQ_NONE; - if (priv->tx_buf) { - if (stat & NPCM_PSPI_STAT_RBF) { - ioread8(NPCM_PSPI_DATA + priv->base); - if (priv->tx_bytes == 0) { - npcm_pspi_disable(priv); - complete(&priv->xfer_done); - return IRQ_HANDLED; - } - } - - if ((stat & NPCM_PSPI_STAT_BSY) == 0) - if (priv->tx_bytes) - npcm_pspi_send(priv); + if (priv->tx_bytes == 0 && priv->rx_bytes == 0) { + npcm_pspi_disable(priv); + complete(&priv->xfer_done); + return IRQ_HANDLED; } - if (priv->rx_buf) { - if (stat & NPCM_PSPI_STAT_RBF) { - if (!priv->rx_bytes) - return IRQ_NONE; - - npcm_pspi_recv(priv); + stat = ioread8(priv->base + NPCM_PSPI_STAT); - if (!priv->rx_bytes) { - npcm_pspi_disable(priv); - complete(&priv->xfer_done); - return IRQ_HANDLED; - } - } + /* + * first we do the read since if we do the write we previous read might + * be lost (indeed low chances) + */ + if ((stat & NPCM_PSPI_STAT_RBF) && priv->rx_bytes) + npcm_pspi_recv(priv); - if (((stat & NPCM_PSPI_STAT_BSY) == 0) && !priv->tx_buf) - iowrite8(0x0, NPCM_PSPI_DATA + priv->base); - } + if (((stat & NPCM_PSPI_STAT_BSY) == 0) && priv->tx_bytes) + npcm_pspi_send(priv); return IRQ_HANDLED; }